﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp1
{
    class Class1
    {
        private string name;

        public Class1(string name)
        {
            this.name = name;
        }

        public double yuan (double r)
        {
            return r * r * 3.14;
        }
        public double zheng(double a, double b)
        {
            return a * b;
        }

    }
}
